#include<iostream>
using std::cout;
using std::endl;

class Point{

public:
    Point(int x,int y)
    :_ix(x)
    ,_iy(y)
    {}
    void print(){
        cout<<_ix<<" "<<_iy<<endl;
    }
protected:
    int _ix;
private:
    int _iy;
};

//公有继承
class Point3D:public Point{

};